diff --git a/library/aes.c b/library/aes.c
index 9dc7b7d..f91d251 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -1064,14 +1064,13 @@
 #endif
 
 #if !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
-    if (mode == MBEDTLS_AES_ENCRYPT) {
-        return mbedtls_internal_aes_encrypt(ctx, input, output);
-    } else {
 #if !defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
+    if (mode == MBEDTLS_AES_DECRYPT) {
         return mbedtls_internal_aes_decrypt(ctx, input, output);
-#else
-        return MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE;
+    } else
 #endif
+    {
+        return mbedtls_internal_aes_encrypt(ctx, input, output);
     }
 #endif /* !MBEDTLS_AES_USE_HARDWARE_ONLY */
 }
diff --git a/library/aesce.c b/library/aesce.c
index 5883e6a..9a82731 100644
--- a/library/aesce.c
+++ b/library/aesce.c
@@ -244,14 +244,13 @@
     uint8x16_t block = vld1q_u8(&input[0]);
     unsigned char *keys = (unsigned char *) (ctx->buf + ctx->rk_offset);
 
-    if (mode == MBEDTLS_AES_ENCRYPT) {
-        block = aesce_encrypt_block(block, keys, ctx->nr);
-    } else {
 #if !defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
+    if (mode == MBEDTLS_AES_DECRYPT) {
         block = aesce_decrypt_block(block, keys, ctx->nr);
-#else
-        return MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE;
+    } else
 #endif
+    {
+        block = aesce_encrypt_block(block, keys, ctx->nr);
     }
     vst1q_u8(&output[0], block);
 
diff --git a/library/aesni.c b/library/aesni.c
index 6c917da..c68b081 100644
--- a/library/aesni.c
+++ b/library/aesni.c
@@ -93,24 +93,25 @@
     ++rk;
     --nr;
 
-    if (mode == MBEDTLS_AES_ENCRYPT) {
-        while (nr != 0) {
-            state = _mm_aesenc_si128(state, *rk);
-            ++rk;
-            --nr;
-        }
-        state = _mm_aesenclast_si128(state, *rk);
-    } else {
 #if !defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
+    if (mode == MBEDTLS_AES_DECRYPT) {
         while (nr != 0) {
             state = _mm_aesdec_si128(state, *rk);
             ++rk;
             --nr;
         }
         state = _mm_aesdeclast_si128(state, *rk);
+    } else
 #else
-        return MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE;
+    (void) mode;
 #endif
+    {
+        while (nr != 0) {
+            state = _mm_aesenc_si128(state, *rk);
+            ++rk;
+            --nr;
+        }
+        state = _mm_aesenclast_si128(state, *rk);
     }
 
     memcpy(output, &state, 16);
@@ -445,12 +446,6 @@
                             const unsigned char input[16],
                             unsigned char output[16])
 {
-#if defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
-    if (mode == MBEDTLS_AES_DECRYPT) {
-        return MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE;
-    }
-#endif
-
     asm ("movdqu    (%3), %%xmm0    \n\t" // load input
          "movdqu    (%1), %%xmm1    \n\t" // load round key 0
          "pxor      %%xmm1, %%xmm0  \n\t" // round 0
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 2ada2eb..1faf1dd 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -157,7 +157,6 @@
 #if defined(MBEDTLS_AES_C)
         case MBEDTLS_ERR_AES_INVALID_KEY_LENGTH:
         case MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH:
-        case MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE:
             return PSA_ERROR_NOT_SUPPORTED;
         case MBEDTLS_ERR_AES_BAD_INPUT_DATA:
             return PSA_ERROR_INVALID_ARGUMENT;